B.dubia colony rapidly crashing

[Salzy]

Hello everyone! My name is Kyle and I joined up to ask some questions and hopefully read and learn more as I go. I'll be honest and say that I don't have a ton of time these days, so I didn't do a lot of searching for answers before making this post. Please help me out though as best as you can! I'm in need of some good advice.

I'm not sure what the reason is behind my colonies decline, but I am easily losing 100 adult roaches per week all of a sudden. All this past season they were breeding extremely well and I was selling off the nymphs and extra adults that were overcrowding the colony. I sold off 4000-4500 small nymphs to a friend at one point. Now, I can't seem to keep them alive.

My care hasn't changed whatsoever...they are still on the same heat and diet and in the same corner of a closet. The only thing that has happened is that I've had an uncontrolable outbreak of fruit flies for some reason. That is the only thing that I can think of that is decimating my roaches. I have no other explanation.

I'm looking for your help or insight if you have any. Before long, there will be nothing left and I'll have to raise up the few nymphs that the adults actually are producing yet. Is there some type of disease that they can get? Is it the fruit flies causing the problems? I'm thinking I may have to just kill off the rest of the colony, toss the bin that I've had them in, and start over. Is there any saving them?

It has been suggested to me that I split the remaining roaches into 2 colonies, and hope that at least one does well and helps to rebound my colony.

Anything else you guys can tell me would be extremely appreciated. Thanks!

[hisserman]

Welcome.

The "fruit flies" are really phorid flies; which are killing your roaches. Try sticky traps or put fine netting up. Other then that, I don't know what you should do.

[vfox]

Fruit and phorid flies don't kill roaches, they simply breed in the waste, old food, and dead roaches really well and appear to be the cause when they are not. They have the potential to stress out the adults and spread disease but it's likely they are just free loaders.

It's likely one of three things are happening. Firstly it could be a generational die-off where adults of the same ages are hitting the end of their life time. It could be a disease that is spreading throughout the adults, or it could be mites.

If I were you I would remove the adults and check them for mites and weakness. Whatever adult has mites or shows signs of weakness should be destroyed. Do the same thing with the nymphs. Completely clean out your housing bin with hot water and a mild soap. Reintroduce the roaches with new egg flats and new food bowls and you should be fine.

Good luck and keep us updated.

[Zephyr]

As vfox suggested, you're going to have to cull your colony.

Mites not even be to blame; I've had colonies crash just because they were way too overpopulated. Even if you sell off half the colony, the stress from living under those conditions will cripple and deform some of your nymphs and you will still have adults dying off.

Starting over with as many healthy suabdult nymphs as you can grab may be your best option here. The alternatives include isolating all the tiniest roaches and using them to start the colony, or isolating a good amount of big, healthy adults and going from there.

[Salzy]

Thanks for the suggestions.

I did a complete overhaul of the bins and everything on Monday night. I hand sorted every single adult and large nymph and anything that even had a missing leg or walked funny or anything I tossed out. I was still able to save probably 75% of them, since they appeared healthy and could still move quickly. I'll continue to sort them out once a week or something to make sure I'm keeping only the best.

I've also separated everything based on size for the most part. Adults to their own bin, large nymphs to another, and small nymphs in another to make it easier for me to use them as feeders. I figured this will help me to monitor how quickly they are dying off or growing.

I did notice that almost all of the roaches that were dying were adults, because I have hundreds of large nymphs that are ready to molt into adults soon. It may have just been the demographics of the colony, and the adults were just at the end of their lives anyway.

The flies are also slowly going away already too. I've only seen a couple in the past few days, so hopefully that is all under control.

Again, thanks for the advice and help. I'll keep you all updated.

[Shaneofall]

Fruit and phorid flies don't kill roaches, they simply breed in the waste, old food, and dead roaches really well and appear to be the cause when they are not. They have the potential to stress out the adults and spread disease but it's likely they are just free loaders.

Just some previous research and experience with phorid flies. There are many species with various parasitic behaviors and levels of aggression directed at tank mates. I had a variety that would lay it's eggs in fresh laid gecko eggs, later to find an incubating chamber full of phorid flies and a completley hollow egg, with one pin size entry/exit hole. Also found one lizard with phoid fly larvae coming out of what was a swollen arm. I would not doubt these guys can be a high priority pest to remove from any colony.